Optimizing Environmental Stress Screening (ESS)

Vibration Excitation Types

• Sine Sweep and Sine Dwell
• Random
• Natural Mode Response
• Distribution of vibration test responses
• Isolation
• Circuit card natural response - frequencies and shapes

Fatigue discussion

• S-N Curve
• Low and high cycle fatigue
• Curve Slope
• Stress / life relationship
• Damage method
• Demonstration of fatigue damage calculation
• Damage contributions - damage rates for excitation types
• Random response and damage distributions - material property effects
• Circuit Cards properties and tolerances - effect on vibration life capability
• Accelerated life testing - equivalent damage discussion

HALT - effective step stress testing - Do's / Don'ts

ESS - screen effectiveness - unit input control

• Response
• Component positions
• ESS optimization
• Determining screen effectiveness for potential flaws

Example applications of PoF vibration methods

Design of experiments - shaker, fixture, axes of vibration

Avoiding blind application of guidelines, rules, buzz words / phrases

PoF analysis, test comparison

PoF analysis methods throughout the electronics development process

Course summary

Award of certificates